CVE-2012-4461

Published: 6 November 2012

The KVM subsystem in the Linux kernel before 3.6.9, when running on hosts that use qemu userspace without XSAVE, allows local users to cause a denial of service (kernel OOPS) by using the KVM_SET_SREGS ioctl to set the X86_CR4_OSXSAVE bit in the guest cr4 register, then calling the KVM_RUN ioctl.

From the Ubuntu security team

Jon Howell reported a flaw in the Linux kernel's KVM (Kernel-based virtual machine) subsystem's handling of the XSAVE feature. On hosts, using qemu userspace, without the XSAVE feature an unprivileged local attacker could exploit this flaw to crash the system.

Status

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-4461
• http://www.openwall.com/lists/oss-security/2012/11/06/14
• http://article.gmane.org/gmane.comp.emulators.kvm.devel/100742
• https://ubuntu.com/security/notices/USN-1688-1
• https://ubuntu.com/security/notices/USN-1689-1
• https://ubuntu.com/security/notices/USN-1696-1
• https://ubuntu.com/security/notices/USN-1699-1
• https://ubuntu.com/security/notices/USN-1704-1
• NVD
• Launchpad
• Debian

Bugs

• https://bugzilla.redhat.com/show_bug.cgi?id=862900
• https://launchpad.net/bugs/1089604